Generally, steam pipes are used as part of a district heating system in many cities carrying steam from central power stations under the streets to heat, cool, or supply power to high rise buildings and businesses. Some businesses and facilities also use the delivered steam for cleaning and sterilization. In addition to providing space and water heating, the steam is used in numerous restaurants for food preparation, laundries and dry cleaners, as well as to power absorption chiller systems for air conditioning. The New York Steam Company began providing this service in lower Manhattan in 1882. Today, Con Edison operates this system that has grown to become the largest commercial steam system in the world. Con Edison now transmits about 14 million tons per year of steam through its pipe system. The steam flows at a relatively high speed and it can reach over 100 miles per hour. It is common to see the emission of vapors from manholes in Manhattan and it mostly caused by external water being boiled resulting from contact with a steam pipe and it does not necessarily represent a leak in the steam system.
One of the concerns to such a system is the excitation of water hammer that may lead to serious consequences including damaged vents, traps, regulators and piping. The water hammer is caused by accumulation of condensed water that is trapped in a portion of horizontal steam pipes. The velocity of the steam flowing over the condensed water causes ripples in the water creating buildup of turbulence and resulting in the water formation of a solid mass or slug that fills the pipe. The slug of the condensed water can travel at the speed of the steam striking the first elbow that is encountered in its path. The force can be comparable to a hammer blow and can be sufficiently large to break the back surface of the elbow.
There is a need for systems and methods that can provide real time monitoring of pipes that operate at high temperature and elevated pressure.